This application is for a five-year extension of funding for the Diabetic Retinopathy Clinical Research Network (DRCR.net) Coordinating Center. The objective of the DRCR.net is to develop and maintain a collaborative network to facilitate multicenter clinical research on diabetic retinopathy, diabetic macular edema and associated conditions, leading and growing causes of vision impairment and blindness in the United States and throughout the world. Its priorities include involvement of community-based practices as well as university-based centers and to collaborate with industry to facilitate investigations and opportunities otherwise not possible, but to do so in a manner consistent with the Network's dedication to academic integrity and optimal clinical trial performance. The Coordinating Center plays a key role in the Network's ability to achieve its goals. During the next funding cycle, the network proposes to complete 5 protocols that are expected to be in progress at the time the funding period begins, initiate approximately 10 new protocols (approximately 1 new major protocol and 1 new minor protocol per year) in diabetic retinopathy, diabetic macular edema and associated conditions, develop and implement new methods for electronic data capture of retinal images to facilitate the conduct of diabetic retinopathy clinical trials, continue to expand the DRCR.net by soliciting the participation of new sites and encouraging the involvement of investigators who recently have completed fellowship training (see Operations Center proposal), continue to educate the DRCR.net investigators on the principles of clinical research, and mentor selected retina specialists to be leaders in clinical trials with specific reference to diabetic retinopathy and associated diseases.